Instrument panels exhibiting two different grain patterns are known in the art. While such panels typically include multiple pieces assembled together (and typically suffering from both fit and finish and tolerancing issues) additional attempts have been made to replicate the appearance of a multiple parts by employing a single piece.
An example of a one-piece trim panel is incorporated into the 2006 Toyota Solara. A portion of a side of the instrument panel has two portions which are painted different colors and exhibit different grain patterns. A knife blade is employed for establishing a groove between the distinguishable grain patterns and, in practice, imparts undesirable sharp corners in the tool which greatly reduces tool life and increases the chance for tool cracking. The final parts produced also exhibit large radius' at the mating of the two portions, and which does not match current desired styling trends of minimal radius'.
Other examples are also known of style lines or grooves incorporated into an existing surface of a vehicle dash or panel. Such lines or grooves are typically for styling purposes and usually do not separate visually differentiable surface grains/patterns or impart a separate part appearance.